But Klein, who drove a school bus for 20 years before spending three years as a monitor, remains as unassuming as she was before learning firsthand how the kindness of strangers can trump the cruelty of four adolescent boys.

‘‘It’s really amazing,’’ Klein said at her suburban Rochester home, still perplexed at the outpouring unleashed by a 10-minute cellphone video of her being ridiculed, sworn at and threatened by a group of seventh-graders last June. They poke at her hearing aid and call her names as she tries to ignore them.

‘‘Unless you have something nice to say, don’t say anything at all,’’ Klein says calmly a few minutes in.

One boy taunts: ‘‘You don’t have a family because they all killed themselves because they don’t want to be near you.’’ Klein’s oldest son committed suicide more than a decade ago.

The video, recorded by a fellow student, was posted online and viewed more than 1.4 million times on YouTube.

When 25-year-old Canadian Max Sidorov was moved to take up an online collection to send her on vacation, more than 32,000 people from 84 countries responded — pledging $703,873 in donations.

‘‘It’s just the way it hits them, I guess. I don’t know. I don’t know,’’ Klein said, still unsure of why it all happened.

Sidorov has called it ‘‘ridiculously more than I expected.’’

Klein used $100,000 as seed money for the Karen Klein Anti-Bullying Foundation, which has promoted its message of kindness at concerts and through books. Most recently, the foundation partnered with the Moscow Ballet to raise awareness of cyberbullying as the dance company tours the United States and Canada.

‘‘There’s a lot I wish I could be doing, but I don’t know how to do it,’’ Klein said.

‘‘I'm just a regular old lady,’’ she added with a laugh.

She has spent some helping family members and friends, and ‘‘the rest is under lock and key’’ for retirement, and maybe a motor home to do some traveling, she said. She wants to get back to her crafts, fix some things around the house, maybe get new carpet and furniture, and take it easy, especially since having a pacemaker implanted in March.

‘‘There are other people who it would probably change dramatically,’’ said Klein’s daughter, Amanda Klein-Romig. ‘‘But for her, no, everything’s the same pretty much. It’s not like she’s jaunting every weekend to a different place.’’

Klein has been to Boston, Toronto and other cities to promote her foundation. She participated in a WNBA anti-bullying event with the New York Liberty in Newark, N.J., and has been invited to appear on ‘‘Raising McCain,’’ a cable television series launching this summer starring Arizona Sen. John McCain’s daughter, Meghan.

‘‘There’s a lot of nice people out there, I have learned that,’’ Klein said. ‘‘And to ignore the negative people.’’

Klein has been criticized by those who say she didn’t do her job that June 2012 afternoon and by others who think she sought out fame and fortune.

‘‘They make it sound like I did this on purpose,’’ Klein said. She didn’t even know the incident had been recorded until being called in to school by administrators and the police.

‘‘She didn’t ask for this,’’ Klein-Romig said.

Klein has met with one of the boys who bullied her. He and his parents came to her home to apologize. The other three sent typed apologies, which she said struck her as less sincere.

‘‘I hope they learned a lesson; they probably didn't,’’ Klein says, shrugging. ‘‘It might have been a big joke to them.’’